Customer Journey: unexpected results from search

when i search in CJ using:

		startDate: '2024-01-10T20:20:39+00:00',
		endDate: d.toISOString(),
		channelIds: ['Chat', 'Voice'],
		identifiers: { "emailAddresses": [ "[email protected]"]}

in the returned results i find the following engagement which does not contain the identifier i'm searching for. now, in other engagements this phone number is present with the email address and so it appears there is some magic going on where previously linked identifiers are remembered and engagements returned even if the identifiers have not been added. is this magic documented anywhere?

{
"identifiers": {
"phoneNumbers": [
"+19176858541"
]
},
"id": "6964c944-51f3-45d2-a041-22f5c42e0a3d",
"status": "COMPLETED",
"direction": "OUTBOUND",
"channels": [
{
"id": "Voice",
"type": "Voice"
}
],
"startDate": "2024-02-09T22:21:50.976Z",
"updateDate": "2024-02-09T22:22:44.463Z",
"endDate": "2024-02-09T22:22:44.463Z",
"conversations": [],
"participants": [
{
"type": "AGENT",
"id": "dda4813b-329a-4e4f-bfc5-47de39211d8e",
"agentDisplayName": "Nick, Agent",
"dialogId": "04951007481707517310",
"channelId": "Voice",
"channelType": "Voice",
"joinedAt": "2024-02-09T22:21:50.979Z",
"leftAt": "2024-02-09T22:22:44.452Z"
}
],
"accountId": "FUDBYY",
"data": {},
"attributes": [],
"queues": [],
"transfers": []
}